DESCRIPTION [provided by applicant]: Brain hypoxia is a component of perinatal ischemia that is increasingly common among low birth weight infants and those suffering ischemia in utero with 100% oxygen (hyperoxia) treatment being a common clinical practice. In addition to resultant child morbidity and mortality, there are delayed cognitive impairments persisting up to eight years later. The overall hypothesis of this program project is that hypoxia/ischemia-associated oxidative stress in postnatal day 7 (P7) rat results in DNA damage, delayed cell death, and inflammation; all risk factors to neuronal development and function. The characterization of the signal transduction pathways that regulate cell death processes and determine outcomes will allow for rational design of interventions to decrease cell death and reduce inflammatory cascades. Specific hypotheses to be tested are that there is DNA damage after hypoxia/ischemia that triggers DNA repair (Project I); that neuronal sparing after hypoxia/ischemia is due in part to Bcl-xL expression (Project II); and that cytokine expression and vascular responses are part of the inflammatory activation of NF-kappaB transcription factors that determine cell death (Project III). Intervention paradigms will be via inhibition of DNA repair processes, injection of Bcl-xL, and modulation of NF-kappaB activation by a "decoy" elements. Characterizations will rely on electrophoretic mobility shift and footprinting assays, Westerns and microaffinity isolation, immunoblot assays, as well as various in situ histochemical and immunocytochemical assays. Transcription factor inhibition and overexpression will be assessed in vitro and in vivo. Lesion damage in the three projects will be determined by immunohistochemistry and MRI techniques sensitive to local edema and blood flow changes. Confounds and integration of observations will also rely on longitudinal MRI studies together with Affymetrix DNA microarray analyses. An understanding of risk factor outcomes may provide therapeutic strategies for children affected by perinatal/ischemia.